I would suggest the best and reliable tool PDS OST to PST converter. The OST to PST converter tool converts the multiple OST files to Outlook PST formats and it also recovers the deleted and inaccessible OST data items such as Sent Items, Journals, Task’s entries, Notes, and drafts, etc. Download the free demo version of the software A free demo edition is also offered to all users
Know more info- http://www.perfectdatasolutions.com/convert-ost-to-pst.html
Try OST to PST Converter App, which is very popular in the data conversion field. It supports the version of Outlook up to 2019. You can easily switch bulk OST files to PST in just a few 3-4 steps, so try this tool. Separately from OST the user store their emails, inbox, sent the item, drafts, delete items, attachments into numerous file formats such as PST, MSG, EML, EMLX, MBOX. This tool is very helpful and provides 100% safe and secure results after conversion.
Cigati OST to PST Converter Software is a complete solution to convert the OST files into various file formats and email clients with ease. It is a full-featured software designed considering the modern user's requirements. OST to PST Converter Software has a simple user-Interface requiring no prior technical knowledge to use this software.